import Vue from 'vue'
// 导入组件
import DeleteFileDialog from './Dialog.vue'
// 使用基础 Vue 构造器，创建一个“子类”
const DeleteFileConstructor = Vue.extend(DeleteFileDialog)

let deleteFileInstance = null
/**
 * 初始化删除文件实例
 * @param {boolean} isBatchOperation 是否为批量删除：true - 批量删除，false - 单文件删除
 * @param {object | array} fileInfo 文件信息，批量时为数组、单文件时为对象
 * @param {number} deleteMode 删除模式：1-删除到回收站 2-彻底删除
 */
const initInstanceDeleteFile = (isBatchOperation, fileInfo, deleteMode) => {
  deleteFileInstance = new DeleteFileConstructor({
    el: document.createElement('div'),
    data() {
      return {
        isBatchOperation,
        fileInfo,
        deleteMode
      }
    }
  })
}
/**
 * 删除文件 Promise 函数
 * @returns {Promise} 抛出确认和取消回调函数
 */
const showDeleteFileDialog = (obj) => {
  // 非首次调用服务时，在 DOM 中移除上个实例
  if (deleteFileInstance !== null) {
    document.body.removeChild(deleteFileInstance.$el)
  }
  const { isBatchOperation, fileInfo, deleteMode } = obj
  return new Promise((reslove) => {
    initInstanceDeleteFile(isBatchOperation, fileInfo, deleteMode)
    deleteFileInstance.callback = (res) => {
      reslove(res)
      // 服务取消时卸载 DOM
      if (res === 'cancel' && deleteFileInstance !== null) {
        document.body.removeChild(deleteFileInstance.$el)
        deleteFileInstance = null
      }
    }
    document.body.appendChild(deleteFileInstance.$el) //  挂载 DOM
    Vue.nextTick(() => {
      deleteFileInstance.visible = true //  打开对话框
    })
  })
}

export default showDeleteFileDialog
